AmJu0nUe?lf97a^m•}     Literature  Relating  to  Pharmacy.  321 
stated  by  the  author,  this  variety  was  unsuited  for  many  pharma- 
ceutical purposes  on  account  of  its  brown,  coarse  appearance. 
For  the  preparation  of  a  soluble  essence  possessing  all  the  flavor 
of  the  ginger  it  was  recommended  to  add  3  drachms  of  powdered 
pumice-stone  to  1  fluid  ounce  of  the  essence,  and  shake  occasionally 
during  twelve  hours.  Then  add  gradually  3  fluid  ounces  of  distilled 
water ;  allow  the  mixture  to  stand  six  hours  and  filter. 
REPORT  OF  COMMITTEE  ON  ATOMIC  WEIGHTS. 
The  fourth  annual  report  of  the  Committee  of  the  American 
'Chemical  Society  on  Atomic  Weights,  has  recently  been  published 
(Jour.  Amer.  Chem.  Soc.,  19,  359).  The  chairman,  Dr.  F.  W. 
Clarke,  gives  the  following  illustration  of  the  practical  value  of  a 
correct  knowledge  of  atomic  weights  in  the  commercial  world  : 
44  There  are  two  rival  values  for  the  atomic  weights  of  chromium. 
One,  52  5  approximately,  based  on  the  old  work  of  Berlin,  is  still 
used  by  European  analysts.  The  other,  52-1,  depends  upon  later 
and  more  accurate  researches,  and  is  used  in  this  country.  Mr. 
William  Glenn,  of  the  Baltimore  Chrome  Works,  informs  me  that 
that  establishment  imports  chrome  iron  ore  by  the  shipload,  the 
value  being  determined  by  a  volumetric  assay,  in  which  the  atomic 
weight  of  chromium  is  involved.  It  is  assayed  in  Glasgow,  with  the 
older  value  for  chromium,  and  in  Baltimore  with  the  modern  datum. 
A  cargo  amounts  to  about  3,500  tons,  and  the  difference  in  price 
due  to  the  difference  between  52-1  and  52-5  for  chromium  amounts 
to  about  $367.50  per  shipload." 
The  following  are  the  recalculated  atomic  weights  according  to 
the  best  authorities,  compiled  down  to  January  1,  1 897: 
H  =  1  O  =  16 
Aluminum    26*91  27*11 
Antimony   119*52  120*43 
Argon   (?)  (?) 
Arsenic   74*44  75 'OI 
Barium   136*39  I37'43 
Bismuth   206*54  208*11 
Boron   io*86  10*95 
Bromine   79*34  79*95 
■Cadmium   111*10  m'95 
Calcium  .   39 '76  40*07 
Carbon   11*92  12*01 
Cerium    i39'io  140*20 
Caesium   131*89  13289 
